작년에 인류에게 알려진 가장 위험한 소행성은 적어도 100년 동안 지구에 충돌하지 않을 것입니다

유럽 ​​우주국(ESA)이 소행성의 날 카운트다운을 시작하면서 2052년에 영향이 배제됨

세계 소행성의 날(World Asteroid Day)에 맞춰 몇 달 동안 전 세계 위험 목록의 최상위에 있던 위협받는 우주 암석이 2052년 4월 2일에 지구와 충돌할 가능성이 있습니다. 이제 유럽 우주국(European Space Agency)의 소행성 팀이 작업 중입니다. 남유럽 천문대(Southern European Observatory)의 전문가들과 함께[{” attribute=””>ESO) has officially removed ‘2021 QM1’ from their asteroid risk list, a result of skilled observations and analysis of the faintest asteroid ever observed with one of the most sensitive telescopes ever constructed.

With Asteroid Day Live 2022 set for June 30, we can safely say that the riskiest asteroid known to humankind in the last year will not impact the Earth – at least not for the next century.

What was it like to track this asteroid? Get the full story in ESA’s fascinating behind-the-scenes look at how European experts handle asteroid risks in the official countdown to Asteroid Day live on June 30, airing at 10:25 CEST on AsteroidDay.org and via ESA WebTV.

Asteroid 2021 QM1, once thought to have a chance of impacting Earth in 2052, was spotted passing through a region of the sky with the Milky Way just behind it. The small, faint, receding asteroid had to be found against a backdrop of thousands of stars, with red crosses indicating the path of the object. Credit: ESO/O. Hainaut

Impact 2052

2021 QM1 was first discovered on August 28, 2021, by the Mount Lemmon Observatory, located north of Tucson, Arizona. At the beginning, nothing stood out as unusual about the discovery – about a dozen new near-Earth asteroids are identified every dark night. Routine follow-up observations were subsequently acquired from telescopes around the globe, but these began to tell a more worrying story.

“These early observations gave us more information about the asteroid’s path, which we then projected into the future,” said Richard Moissl, ESA’s Head of Planetary Defense.

“We could see its future paths around the Sun, and in 2052 it could come dangerously close to Earth. The more the asteroid was observed, the greater that risk became.”

단 며칠 밤의 관측을 기반으로 한 궤도 계산은 약간의 불확실성이 있기 때문에 소행성이 발견된 직후 ESA의 위험 목록에 추가되고 추가 데이터가 수집되면 제거됩니다. 확신을 줄인다. , 그리고 소행성은 안전한 것으로 판명되었습니다. 이 경우에는 불가능했습니다.

불행한 우주 정렬

위험이 증가하는 것처럼 보였을 때 완벽한 우주 정렬이 발생했습니다. 소행성의 경로는 지구에서 볼 때 태양에 더 가까워졌고 호스트 항성의 밝은 빛으로 인해 몇 달 동안 볼 수 없게 되었습니다.

2021 QM1이 발견된 직후 지구에서 본 하늘의 태양 가까이 지나갈 때 궤도를 돌고 있습니다. 크레딧: ESA

유럽우주국(European Space Agency)의 NEOCC(Near-Earth Object Coordination Center)의 천문학자인 Marco Micheli는 “우리는 그저 기다려야만 했습니다.”라고 설명했습니다.

“그러나 일을 멈추기 위해 우리는 2021 QM1이 현재 궤도에서 지구에서 멀어지고 있다는 것을 배웠습니다. 즉, 태양의 눈부심에서 벗어날 때쯤에는 너무 희미하여 감지되지 않을 수 있습니다.”

기다리는 동안 그들은 준비했습니다.

지구상에서 가장 강력한 망원경 중 하나에 우선 액세스

유럽남방천문대 초대형 망원경(VLT) 준비되어 있었습니다. 50미터 높이의 소행성이 햇빛에서 멀어지고 기상 조건이 허용되면 ESO의 VLT는 사라지는 암석에 8미터 거울의 초점을 맞출 것입니다.

ESO의 초거대망원경(VLT) 뒤에 있는 칠레의 극적인 월몰. 달이 지면 반대편 수평선에서 해가 떠오르려고 합니다. VLT(Very Large Telescope)는 긴 밤의 관찰 끝에 이미 눈을 감았고, 망원경 운영자와 천문학자는 낮에 기술자, 엔지니어 및 천문학자가 새로운 근무일을 위해 깨어나는 동안 잠을 자고 있습니다. 작업은 세계에서 가장 생산적인 천문대에서 결코 멈추지 않습니다. 크레딧: G.Gillet / ESO

ESO의 천문학자인 올리비에 에노(Olivier Hainaut)는 “위험한 소행성을 발견하는 데 짧은 시간이 걸렸다”고 설명했다.

“설마하게도 그것은 하늘의 한 영역을 통과하고 있었다.[{” attribute=””>Milky Way just behind. Our small, faint, receding asteroid would have to be found against a backdrop of thousands of stars. These would turn out to be some of the trickiest asteroid observations we have ever made”.

Faintest asteroid ever observed

Over the night of May 24, ESO’s VLT took a series of new images. The data arrived and Olivier and Marco began to process them, stacking subsequent observations on top of each other and removing the background stars: it took some time.

ESO’s Very Large Telescope captures 2021 QM1 which for months topped risk lists around the globe. This pivotal sighting ruled out Earth impact in the year 2052. Over the night of May 24, the European Southern Observatory’s Very Large Telescope took a series of images of an asteroid that had topped risk lists around the globe for months. These images were some of the trickiest asteroid experts had taken, as the faint asteroid 2021 QM1 receded from view against a very starry backdrop. A series of images were processed, stacked on top of each other and stars were removed, revealing the faintest asteroid observed. Credit: ESA

The result? A positive detection of the faintest asteroid ever observed. With a magnitude of 27 on the scale used by astronomers to describe the brightness of objects in the sky, 2021 QM1 was 250 million times fainter than the faintest stars visible to the naked eye from a dark spot. (In this astronomical scale of visible magnitudes, the brighter an object appears the lower the value of its magnitude, while the brightest objects reach negative values, e.g. the Sun is magnitude -27).

Olivier was certain this small blur was in fact an asteroid, and Marco was certain that given its location, it was our asteroid.

Safe at last?

With these new observations, our risky asteroid’s path was refined, ruling out an impact in 2052, and 2021 QM1 was removed from ESA’s risk list. Another 1,377 remain.

The position of each asteroid at 12:00 CEST on June 13, 2022, is plotted. Each asteroid is a segment representing its motion over 10 days. Inner bodies move faster around the Sun (yellow circle at the center). Blue represents the inner part of the Solar System, where the Near Earth Asteroids, Mars crossers, and terrestrial planets are. The Main Belt, between Mars and Jupiter, is green. The two orange ‘clouds’ correspond to the Trojan asteroids of Jupiter. Credit: © ESA/Gaia/DPAC; CC BY-SA 3.0 IGO, Acknowledgments: P. Tanga (Observatoire de la Côte d’Azur)

More than one million asteroids have been discovered in the Solar System, almost 30 000 of which pass near Earth, with many more expected to be out there. ESA’s Planetary Defence Office, NEOCC and astronomers around the globe are looking up to keep us safe, working together to ensure we know well in advance if an asteroid is discovered on a collision course.

Watch Asteroid Day Live

How worried are the world’s asteroid experts? How did it feel to track humankind’s most risky asteroid? Get the full story in ESA’s 30-minute program counting down to Asteroid Day live on June 30, airing at 10:25 CEST on AsteroidDay.org and on ESA WebTV.

Fallen trees at Tunguska, Imperial Russia, seen in 1929, 15 km from epicenter of the aerial blast site, caused by the explosion of a meteor in 1908. Credit: Photo N. A. Setrukov, 1928

Asteroid Day is the United Nations-sanctioned day of public awareness of the risks of asteroid impacts, held annually on June 30. This year sees its return to Luxembourg for an in-person event following two years of living entirely in the virtual realm. Asteroid experts from ESA, from across Europe and worldwide will converge on the city to take part in a packed four-hour live program of panels and one-on-one interviews.